//
// pch.h
//
#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <iostream>
#include <cstring>
#include <string>
#include <fstream>
#include <streambuf>
#include <map>
#include <vector>
#pragma once
#include "gtest/gtest.h"
using namespace std;
int gen_chain_char(vector<string> words, int len, vector<string>& result,
    char head, char tail, char reject, bool enable_loop);
int gen_chain_word(vector<string> words, int len, vector<string>& result,
    char head, char tail, char reject, bool enable_loop);
int gen_chains_all(vector<string> words, int len, vector<string>& result);
